Crack Mechanism of Al@Al2O3 Nanoparticles in Hot Energetic Materials

K Zhong and LL Niu and G Li and CY Zhang, JOURNAL OF PHYSICAL CHEMISTRY C, 125, 2770-2778 (2021).

DOI: 10.1021/acs.jpcc.0c10479

The addition of aluminum (Al) powders to energetic formulations is popular to increase energy, while it gives rise to an issue of how to maximize energy release therein. Cracking Al particles is an efficient way to enhance reactivity and energy release. In the present work, we confirm the crack of Al nanoparticles in hot energetic materials by molecularly simulating the evolution of Al@Al2O3 nanoparticles (ANPs) with imperfect shells and Al slabs covered by perfect Al2O3 layers in a heated widely applied energetic material, 1,3,S-trinitro-1,3,5-triazinane (RDX). The thickening of imperfect shells at an ambient condition by the outward migration of core AI atoms to react with RDX is observed. This thickening is helpful to strengthen the shells and hold melted Al and enhance the internal stress until the crack. While the perfect shells protect the reactions between core Al atoms and RDX, they also induce a crack when heating ANPs at a high temperature. This work is also expected to present an atomic perspective about the structural evolution of other active metallic particles in the wavefront as an extreme in the application.

Return to Publications page